The effects of tDCS on physical performances: A systematic literature review

Objectives - Transcranial direct current stimulation has been gaining momentum in the scientific literature. The objective of this literature review was therefore to identify and analyze randomized and controlled trials on the effects of transcranial stimulation on muscle strength and muscular endurance. Materials and methods - Two databases (Medline and Scopus) were used to search for randomized controlled trials on the effects of transcranial stimulation on parameters of strength and endurance in healthy subjects. Their quality was assessed by the PEDro scale. PROSPERO registration number: CRD42018118053. Results - Thirty-six randomized controlled trials, 12 of which were single-blind, were included, totaling 542 subjects. Thirteen of 23 articles evaluating the effects of tDCS on endurance show a positive effect. Similarly, 8 of 19 articles evaluating the effects of tDCS on strength show a positive effect. Conclusion - Despite a great diversity in the parameters of stimulation (notably the electrodes) and the methods for evaluating the effects of transcranial stimulation, it seems that transcranial stimulation is a non-invasive, safe, inexpensive method with few undesirable effects which could be an interesting adjunct during training to improve physical performance.